Elevator systems



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sLsvAroa SYSTEMS Application Septemher 27, 1956, Serial No. 612,552

23 Claims. (Cl. IS7-m29) "this invention relates to elevator' systemsand it has partieuiar relation to elevator systems which are designed for operation without car attendants.

Although aspects of the invention may be employed in elevator systems having car attendants, the invention is particularly desirable for elevator systems of the automatic type which do not have car attendants. For this reason, the invention will e discussed with particular reference to such operatorless systems.

When an elevator car in an operatorless system. stops @t a landing, such as a floor of a building or structure, t is the practice to hold the elevator car at the floor tor a substantial time in order to permit loading and unloading of the elevator car. This time is referred to as s non-interference time. ln the prior art systems, thc ncninterference time may be of the order of 5 or more seconds for each stop.

As shown in my copending patent application Serial No. 427,476, liled May Ifl, 1954, which issued as Ponent 2,785,772 on March 19, 1957, of which this is a continuation-impart, the non-interference time may he varied in accordance with the requirements for each of the floors at which a stop is made. To this end, the elevator system is designed to hold an elevator car at z. licor at which the elevator stops for a non-interference suhstantial time, such as 5 seconds.

The non-interference time for a car call may differ from that employed 'for a door call. Thus, if a pas senger within the elevator ear registers a call for a licor, the elevator car .may be held at such lloor for a noreioterference time of the order of say three seconds. l-iowever, it the elevator' car stops in response to a oor call registered oy an intending passenger at one of the intermediate floors, a longe non-inteitererrce time, to allow o. passenger to walk to the car that is stopping ll .fn the farthest point of the corridor, such 5 to 7 seconds r he employed.

lo one ,/stem to which the invention may he applied a nondnterferenee time is provided the rer sich stop of the order o ooe-half second. The non-interference time simil :if is reset for a time or" the order ot one halt second exch t a successive pass leaves or enters the elevator it no passenger enters or leaves the elevator car after the predetermined time has elapsed for a period in excess or" one-half second, the door starts to close. Once the door starts to close, it may continue to its completely closed position despite the attempt ate ,47,089 Patented Aug. 12, 1958 el additional passengers to enter the elevator car or leave the elevator car provided the elevator car is in conditie-n to run. Alternatively, the elevator car door may be conditioned to open each time a passenger attempts to enter or leave the elevator car before the elevator car door completely closes. When this happens, the door does not start to close until a short time such as one-half second after the last passenger passes through 'the doorway.

lf the elevator car stops in response to a registered floor call at an intermediate door, the elevator car door again is opened and remains open for a substantial noninterference time, such as live seconds. However, if

person enters or leaves the elevator ear, the non-interference time is reset for a smaller value, such as two seconds. lf succeeding persons enter or leave the elevator car at close enough intervals, the non-interference time is reset for each of the persons for a time which may be of the order of one-half second in order to delay the reclosure of the door.

if the elevator car stops at an intermediate floor .in response to a registered licor call and is assigned to reverse at such floor, the door may open for a non-interference time of the order of tive seconds. ln this case, entry of a person into the car or departure of a passenger from the car may reset the non-interference time to a smaller value of the order of one-half second. Each succeeding person entering or leaving the elevator car within suitable intervals may reset the non-interference time for an interval of the order of one-half second to delay reclosure of the door.

The movement of a passenger or an intending passenger into or out of the elevatorcar can be determined by transmitting energy into the passage traversed by such passenger. interruption of such energy path by a passenger is ascertained by a suitable detector.

lu some cases, a passenger may attempt to prevent the closure of the door for an unreasonably long time by standing in the path of the transmitted energy. lf the energy is interrupted for an unduly long period, such as four seconds, a closing movement of the door is initiated promptly at the close of such period. Desirably the door may be provided with a protective edge which initiates the stopping or reopening of the door if the door reaches a person located in the closing path of the door. lf -as the door reopens the path for the energy is reestablished the door will remain open for the required one-half second and will not start to reelose as long as the path is interrupted at less than one-halt` second intervals.

After movement into or out of the elevator car starts, successive loads or passengers ordinarily follow the first load or passenger rapidly. Each load or passenger yafter the tirst one resets the non-interference time for an additional small time of the order of one-half second. Consequently, Waste time is substantially eliminated and the efficiency of the elevator system is materially improved.

At terminal doors, it may be desirable to control the departure of elevator cars by a suitable dispatcher for the purpose of maintaining adequate spacing of the elevator ears. In such a case, the variable non-interference time is still desirable for the intermediate floors or landings served by each elevator car. lf the car is loading or unloading after a closing operation of the elevator car door is initiated by the dispatcher, the closure of the door may be prevented by operation of the detector.

In a suitable system, an elevator car is provided with a passage through which load, such as a passenger, may enter and leave the elevator car. The passage may be exposed or closed by a door which is automatically opened as the elevator car reaches a predetermined load transfer position which ordinarily is a landing or floor of a building. Upon expiration of the non-interference time, the door may be closed for the purpose of permitting departure of the elevator car.

A signal or energy is established or transmitted across the passage. A detector is provided which is responsive to a function of the signal or energy. For example, the detector may be responsive to the presence or absence of radiant energy. if a load, such as a passenger, enters the area through which the radiant energy is projected, the detector senses the presence of such load. The detector, in turn, controls mechanism which, in response to the movement of the load through the passage, resets the non-interference time in the manner previously described. If the detector receives no radiant energy for more than a predetermined time the door may be promptly closed.

' Other expedients may be employed for expeditinf' closure of the elevator car door. Thus shortly before the elevator car door is assigned to close, a suitable signal may be operated to warn persons of the impending closure of the door. Such a signal may be in any suitable form such as a lamp or a voice message instructing persons to clear the doorway. A buzzer is quite suitable for such ra signal.

If the elevator car door fails to close within a reasonable time, a second signal desirably is operated. This signal may be of the same general type as the first signal.

Door speed and door force may be controlled for the purpose of assuring door closure. If the elevator car door has remained open for more than a reasonable time, the closing force may be increased for the first part of the closing movement in order to force from the path of the door any obstruction impeding door closure. Desirably, the door under such circumstances may start its closing movement at a normal speed. However, if the door thereafter reaches an obstruction in the closing path of the door, the speed of the door may be reduced until the obstruction is removed.

If the closure of the door is prevented for more than a reasonable time, a closing force may be exerted on the door continuously until the door closes. The system may be so arranged that the closing force is exerted unless safety edges on both sides of the door opening are operated.

ln the foregoing discussion, the operation resulting from an interruption of the beam of light is independent of the direction of movement of the load through the doorway. A system may be employed wherein a control is exercised which is dependent on the direction in which load moves.

Thus, first and second detectors may be provided which are responsive to different positions of a load. For example, if the load is represented by a passenger entering the elevator car, the movement of the passenger into the elevator car operates the first detector before operating f the second detector. For a reverse movement of the load the detectors operate in the inverse order.

The detectors are employed for initiating control operations which are dependent on the direction of movement of the load. Thus, an elevator car may be provided with a non-interference time which may be of the order of 5 seconds. If the elevator car stops in response to a registered car call, movement of load through the doorway of the elevator car resets the non-interference time to a smaller value such as 1/2 second. If the elevator car stops in response to a registered oor call, movement of load into the elevator car resets the non-interference time to an intermediate value such as 2 seconds. If the elevator car stops at a door for which both car and floor calls are registered, movement of load out of the elevator car does not reset the non-interference time. However, movement of load into the elevator car resets the non-interference time to an intermediate value such as 2 seconds.

It will be recalled that the starting of cars from a terminal floor may be controlled by a suitable dispatcher..

Such a dispatcher may select elevator cars to leave a terminal floor successively. A substantial time is provided between the dispatch of successive elevator cars for the purpose of' assuring proper spacing of the elevator cars.

If an empty elevator car reaches a terminal tloor and is not selected as the next elevator car to leave the terminal floor, a problem arises because of the fact that the door of the elevator car remains open for its non-interference time. Prospective passengers at the terminal oor tend to enter any elevator car having an open door. The entry of such passengers into an elevator car which is not selected to leave the terminal tloor interferes with efficient operation of the system.

ln accordance with the invention, the non-interference time of an elevator car, which stops at a terminal floor, is substantially shorter than the non-interference time available at intermediate floors. For example, if a noninterference time of the order of 5 seconds is .employed for intermediate iioors, the interference time at a terminal floor may be of the order of 2 seconds. Such a decrease materially reduces the probability of the entry of prospective passengers into an elevator car which is not selected as the next elevator car to leave the terminal floor.

This aspect of the invention is particularly suitable for an elevator car which is provided with mechanism for maintaining the elevator car door open or for reopening an elevator cai door in response to the presence of a passenger in the closing path of the door. Under such circumstances, passengers within the elevator car have ample time to leave the car following a stop at a terminal floor whereas prospective passengers at the terminal oor have comparatively little time within which to enter an elevator car which is not selected to leave the terminal floor.

Despite the foregoing reduction in non-interference time at a terminal floor, it is still possible that a prospective passenger at the terminal oor will succeed in entering an elevator car which is not selected to leave the terminal floor, and his entry may be followed by closure of the elevator car door. In accordance with an aspect of the invention, attempted registration of a car call by such passenger initiates a reopening of the door of the elevator car. In a preferred embodiment of the invention the attempt to register a car call additionally operates a signal which notities the passenger that the elevator car is not selected to leave the terminal oor or that another elevator car will leave iirst.

If an elevator car door is equipped with a safety edge, a person sometimes will hold the door in its open position for an undue length of time by operating the safety edge with his hand. In order to discourage such operation the invention contemplates mechanism for applying a substantial force to the persons hand. This may be effected by rendering the safety edge ineffective for a brief interval following initiation of a door-closing movement or until the elevator car door has traveled a short distance from its fully-open condition. Thus, in a preferred embodiment of the invention the safety edge may be rendered ineiective until the elevator car door has moved a distance of the order of l or 2 inches from its fully-open position.

As the door completes a closing movement it is conceivable that a persons hand or a small object may be introduced into the closing path. Under these conditions the door may be reopened for a small distance sufficient to permit withdrawal of the hand or object. The door then may be reclosed.

Should the elevator car door be provided with mechanism maintaining the door open or reopening a closing door in response to the presence of a person at any position within the closing path `of the door, door closure may be expedited by rendering such mechanism ineffective until the door has completed a substantial closing movement. Thus, in a preferred embodiment of the invention the mechanism is rendered inelfective to maintain the door open or to reopen a closing door until the door has traveled a substantial distance such as l0 inches from its fully-open position. Since a person often will clear the closed path of a door during this l0 inch movement of the door, a number of unnecessary door-opening operations are avoided.

Confusion and distress sometimes follow the opening of an elevator car door while the elevator car is stopped and displaced from a oor. This is particularly true if the elevator car is unduly loaded. ln accordance with an aspect of the invention overload protective mechanism is effective for preventing movement of the elevator car only if the elevator car is at a oor. Preferably, the overload protective mechanism is effective only if the elevator car door is open. ln the event that the elevator ear stalls while it is displaced from a floor, the overload protective mechanism may be rendered elective despite such displacement of the elevator car and despite the fact that the elevator car door may be closed.

ln order to conserve time it is the practice to start an opening operation of the elevator car door while the elevator car is still approaching a door at which it is to stop. If the elevator car is heavily loaded, the ear may sto-p at a substantial distance from the iloor with its door open. Even though the elevator car is provided with automatic leveling equipment, the elevator car still may stop at a point substantially displaced from a tloor before the leveling mechanism takes control of the elevator car. In order to prevent such operation the invention contemplates that the elevator car door will start to open in `advance of a iloor only if the elevator car load is below a predetermined value. if the elevator car is heavily loaded, the initiation of the opening operation of an elevator car door is delayed. This delay is preferably suliicient to assure that the car is stopped before such opening and preferably sumcient to permit prior deenergization of the motor driving the elevator car.

lt is therefore an object of the invention to provide an elevator system having improved door operation.

lt is a further object of the invention to provide an improved elevator system wherein an elevator car is held at certain of its stops for a substantial non-interference time and at other of its stops for a shorter non-interference time.

lt is also an object of the invention to provide an ele-l vator system wherein an elevator car has a shorter noninterference time at a dispatching tloor than its noninterference time at an intermediate hoor.

It is an additional object of the invention to provide an elevator system wherein an elevator car at a dispatching floor which is not selected to leave the dispatching oor and which has its door closed reopens its door in response to attempted registration of a car call.

Still another object of the invention is the provision of an elevator system wherein overload protective mechanism is effective only if an elevator car is stopped at a floor.

It is also an object of the invention to provide an elevator system wherein overload protective mechanism is effective only if an elevator car is stopped at a Hoor with its door open.

It is a further object of the invention to provide an elevator system wherein the door of a heavily loaded elevator car does not open in advance of a oor whereas a door of an elevator car not so loaded may open as the car approaches the licor at which it is to stop.

It is an additional object of the invention to provide an elevator car system wherein an elevator car door provided with protective edge mechanism can be reopened in response to operation of such mechanism only after the door has moved a substantial distance from its fully-open position.

It is another object of the invention to provide an elevator car system wherein door reopening mechanism 6 responsive to the presence ot an object in the closing path of the door is effective only after the elevator car door has moved a substantial distance from its fully-open position.

It is still another object of the invention to provide an elevator car system wherein an elevator car door which reaches an obstruction shortly before it arrives at fully-closed position is reopened for a short distance after which the door resumes its closing movement.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure l is a schematic view with parts in elevation and parts broken away of an elevator system which may embody the invention;

Fig. lA is a View in section with parts broken away showing an elevator car employed in Fig. l associated with a hoistway;

Figs. 2, 3 and 4 are schematic views including circuits in straight-line form of a control system embodying the invention;

Fig. 5 is a schematic View including circuits in straightline form of a modified control system embodying the invention;

Fig. 6 is a view in section showing an elevator car associated with a hoistway and embodying a modilied form of the invention;

Fig. 7 is a schematic view including circuits in straightline form of a modified control system embodying the invention;

Fig. 8 is a View in section showing an elevator car associated with a hoistway and illustrating modied detectors which may be employed in the circuits illustrated in the preceding figures; and

Figs. 2A, 3A, 4A, 5A and 7A are key representations of electromagnetic relays and switches employed in the circuits of Figs. 2, 3, 4, 5 and 7. If Figs, 2, 3, 4, 5 and 7 are horizontally aligned respectively with Figs. 2A, 3A, 4A, 5A and 7A, it will be found that coils and contacts of the switches and relays appearing in the key representations are horizontally aligned with the corresponding coils 'and contacts shown in these circuits.

Although the invention may be incorporated in an elevator system employing various numbers of elevator cars serving buildings or structures having various numbers of oors, the invention can be described adequately with reference to an elevator system having four elevator cars serving a building having live iioors. The elevator cars may be dispatched from any desired lloors. The elevator cars will be assumed to be dispatched between the rst i'loor and the upper terminal or iifth floor.

Because of the complexity of such systems, certain conventions have been adopted. The elevator cars will be identified by the reference characters A, B, C and D. Since the circuits for the cars are similar, substantially complete circuits are shown for the cars A and B. Components associated with the cars C and D are discussed only as required.

Components associated with the elevator cars B, C and D which correspond to a component of the elevator car A are identified by the same reference character employed for the co-mponent of the elevator ear A preceded by the letters B, C and D, respectively. For example, the reference characters U, BU, CU and DU designate up switches, respectively, for the elevator cars A, B, C and D. The discussion will be directed primarily to the apparatus and circuits for the elevator car A.

The various relays and switches employed in the circuits may have break or back contacts which are closed when the relay is deenergized and dropped out. The break contacts are open when the relays or switches are energized and picked up.

The relays and switches also may have front or make contacts which are opened when the switches and relays are deenergized and dropped out, These contacts are VV7 closed when the switches and relays are energized and picked up. In the drawings the various switches and relays are shown in so far as possible in their deenergized and dropped-out conditions.

Each set of the contacts associated with a relay or switch is identified by the reference character associated with the relay or switch followed by a numeral identifying the specific set of contacts. Thus, the reference characters U1, U2 and U3 designate, respectively, the rst, second and third sets of contacts of the up switch U.

ln order to facilitate the presentation of the invention, the apparatus shown in the figures will be brieily set forth, and the operation of the complete system thereafter will be discussed. The system includes in part the following apparatus:

Apparatus specic to cai' A Apparatus common to all cars 2DR to SDR-Down hoor-call storing relays Z UR to 4 UR-Up hoor-call storing relays FGURE I Fig, 1 illustrates the structural relationships of the elevator cars A, B and associated apparatus with reference to the building structure which the elevator cars are intended to serve. v

The elevator car A and a counterweight 10 are secured to opposite ends of a rope or cable 11 which passes over a sheave The sheave 13 is mounted on the shaft ld of an elevator driving motor 1S. The shaft 14 also carries a brake drum i6 with which a brake 17 of the conventional spring-applied electrically-released type is associated. The motor l5 is secured to the door 1S of a penthouse located in the structure which the elevator car is intended to serve.

ln order to simplify the association of control circuits with the elevator car A. a control device 19 is provided which is operated in accordance with a function of the movement of the elevator car A. In the specific embodiment of Fig. l, the control device takes the form of a tloor selector which includes an insulating panel 20 and `a brush carriage 2l, A Screw 22 is mounted for rotation relative to the panel 2d. This screw conveniently may be coupled through suitable gearing to the shaft 14 for rotation in accordance with movement of the elevator car A.

The brush carriage 21 is in threaded engagement with the screw 22. As the elevator car A moves upwardly, the brush carriage 21 is moved upwardly but at a rate much slower than the rate of movement of the elevator car. Similarly, when the elevator car A moves downwardly, the brush carriage 21 also moves downwardly at a slower rate.

The panel 2t) carries a plurality of contact segments which are insulated from each other. Thus, the Contact segments a?. to a5 are arranged in a row on the panel 20. As the e car proceeds upwardly from the basement, a brush mounted on the carriage 21 successively engages the contact segments a2 to a5, as the elevator car approaches respectivelyI the iloors 2 to 5 of the structure,V

it will be understood that the Contact segments n2 to ad d from each other in accordance with the spacings the iloors. As it will be pointed out below, these Contact segments are employed with circuits controlling,v the stopping of the elevator car during up travel in response to car calls.

As a further example, the panel 20 has a single Contact segment el which is engaged by a brush 24 mounted on the carriage 21 only when the elevator car A is adjacent the first or dispatching oor. As will be pointed out below, this contact vsegment is employed in controlling the operation of a dispatching device.

lt will be understood that a number of rows of contact segments and a number of brushes may be employed in the floor selector. However, the foregoing discussion is believed suhicient to illustrate the mechanical relationships of these contact segments and brushes.

Certain apparatus is mounted on or in the elevator car A. Thus, car-call buttons 2c to 5c are provided for registering car calls for the second, third and fourth oors, respectively.

A slowdown-inductor relay E is provided for the purpose of initiating a slowdown of the elevator car A as it approaches a door at which it is to stop. The inductor relay may be of conventional construction and includes two sets of break contacts E1 and E2. When the coil of the inductor relay E is energized, the contacts remain in the positions illustrated in Fig. l until the relay is adjacent an inductor plate located in the hoistway of the elevator car A. For example, when the coil of the inductor relay E is energized and the inductor relay is adju-` cent the magnetic plate UEP for the second oor, the magnetic circuit is completed, which results in opening of the break contacts E1. open until the coil of the inductor relay E is deenergized.

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The inductor plate UEP is positioned to be reached by the inductor relay E as the elevator car approaches the second Floor for the purpose of initiating slowdown of the elevator It will be understood that a similar inductor plate is lf the coil of the inductor relay E is energized during down travel of the elevator car, and if the relay reaches the inductor plate DEP for the second door, a magnetic circuit is completed which results in opening of the break contacts E2. open, the conta-ets remain open until the coil is deenergized. The inductor plate DEP is so positioned that it initiates slowdown of the elevator car A a suitable distance from the second floor. A similar inductor plate would be similarly associated with each of the floors at which the elevator' car A is to stop during down travel.

The elevator car A also carries a stopping inductor relay F which is similar in construction to the inductor relay E. This relay is employed for initiating a stopping operation of the elevator car A, The stopping inductor relay F cooperates with inductor' plates UFP and DFP in a manner which will be clear from the discussion of the cooperation of the slowdown inductor relay with the inductor plates UEP and DEP. lt the coil of the relay F is energized and if the elevator car is to stop at the second iloor while traveling up, when the inductor relay F reaches the in- When open, the contacts remain f ductor plate UFP a magnetic circuit is completed which results in opening of the break contacts FI. This initiates a stopping operation of the elevator car. An inductor plate similar to the plate UFP is similarly associated with each of the floors at which the elevator car A is to stop during up travel thereof. lt the elevator car A during down travel is to stop at the second door, the coil of the stopping inductor relay F is energized, and when the inductor relay reaches the inductor plate DFP for the second floor, a magnetic circuit is completed which results in opening of the contacts F2.. This initiates a stopping operation of the elevator car A. lt will be understood that an inductor plate similar to the inductor plate DFP is similarly associated with each' of the floors at wlhich the elevator A is to stop during down travel there` oi.

The elevator car A also carries a mechanical switch 63 which is positioned to be operated by cams 2o located in the hoistway associated with the elevator car. The mechanical switch 63 normally is closed and is opened by a cam 26 when the elevator cai` A is adjacent the rst or dispatching iioor and by a similar cam when the car is at the upper terminal oor. It will be understood that other mechanical switches may be operated in a similar manner by the elevator car A.

An intending passenger on the fourth oor may regis-- ter a floor call for elevator car service in the up direction by pressing a button of a push-button switch 4U. A similar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in an up direction.

If the intending passenger at the fourth floor desires to proceed in a down direction, he may press the button of a push-button switch 4D located at the fourth door. A similar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in a down direction.

The elevator car A is provided with a door DP which is mounted to slide across the passage through which passengers enter and leave the elevator car. The door is moved by means of a lever 28 which is pivotally mounted on the car by means of a pivot 28A. The lever 28 is moved in a clockwise direction about a pivot by means of a door-close solenoid DC for the purpose of closing the passage and is moved in a counterclock- Wise movement about its passage to open the door by means of a door-open solenoid DO.

When the door is open an objectdetecting device is effective. This device preferably includes, a signal or energy which is projected across .the passage through which passengers enter and leave the elevator car. This signal may be of any type which can be modified by the movement of a passenger through the passage and in which the modiiication produced by such movement may be detected. For example, the signal may be in the form of infrared radiant energy or ultra-violet radiant energy. As a further example, supersonic energy may be projected across the passage. However, it will be assumed that the energy is in the form of visible light which is produced by a lamp LAI mounted on the edge of the door which is the leading'edge during a closing movement of the door. The light is in the form of a beam which is focused in any suitable manner on a suitable detector such as a photocell PCI. The output of the photocell may be amplified by means of an amplier AMI which is supplied with electrical energy from a suitable source and the output of the amplifier is applied t a relay PRI. The relay PRI may be designed to be picked up as long as the photocell PCI receives the beam of radiant energy. Detectors of this type are well known in the art. Examples of such detectors may be found in the Kinnard et al. Patent 1,822,152 and in the Ellis, Ir., Patent 1,947,079.

Although a single beam may sufce, in some cases it is generally desirable to employ a plurality of beams.

10 Such beams'may be produced by interposing suitable retiectors between the lamp LAI and the photocell PCi to reect a beam across the passage several times before it reaches the photocell. However, for present purposes, it will be assumed that separate lamps and photocells are employed for each of the beams. Thus, in Fig. 1A, a second lamp LA2 is provided for projecting energy towards a photocell PC2 which is associated with an amplier AM2 and a relay PRZ.

In the embodiment thus far described, the lamp LAI is mounted on one edge of the door DP. If desired, a lamp and a photocell may be placed in any positions wherein the beam between the lamp and photocell is interrupted by the entry of load into the elevator car or the departure of load from the elevator car. Thus the beam may be located between the car and hoistway doors or it may be adjacent the hoistway door. A beam positioned about twelve inches above the floor has been foundv suitable.

In Fig. IA, a hoistway door DPH is provided which is coupled to the door DP `for movement therewith when the elevator car is stopped at a floor. It will be understood that a separate hoistway door DPH is provided for each of the floors served by the elevator car. The coupling of the two doors may be eifected in a conventional manner as by a vane DPV which is secured to the door DP for reception in the slot of a slotted bloei; DPE which is mounted on the hoistway door DPH.

The hoistway door DPH is moved to close and expose a hoistway passage through which load enters and leaves the elevator car. As shown in Fig. 1A, the lamp LAZ is mountedon a hoistway wall or door jamb to protect radiant energy across the hoistway passage towards the photocell PC2 which also is mounted on a hoistway wall. By inspection of Fig. 1A, it will be observed that the radiant energy transmitted from the lamp LAZ to the photocell PC2 is interrupted each time a passenger enters or leaves the elevator car.

If desired one lamp, such as the lamp LAI, through suitable lenses may direct a first beam towards the photo cell PCI and a second beam towards the photocell PC2. This reduces the number of lamps required.

Movement of the door DP operates a number of switches. Thus, inits open position the door holds open switches 38, 38A and 33C which are biased towards closed conditions. In addition, the door holds closed a switch 38B which is biased towards open condition. As the door starts to close switch 3S opens. After the door has traveled predetermined distances from open position (eg. one inch for switch 38A and ten inches for switch 38B) the switches 38A and 3dB are permitted to operate to closed and open conditions respectively. As the door reaches fu1ly-closed position, it operates a switch 33 from open to closed condition.

If desired, the edge of the door DP, which is the leading edge during a door-closing movement, may have an object-sensing device such as a safety-edge SE of conventional type. When such an edge reaches an obstruction, it opens switches SEI, SEZ, SE and which may be employed in circuits to stop or reopen the door or for other purposes. If center-opening doers are employed, a separate safety edge may be provided for the edge ot' each door which is a leading edge during closing movement. In the present case, it will be assumed that the second safety edge SEA is located on the elevator car adjacent the photocells PCI, PC2. The safety edge SEA operates switches SEAI and SEA2 for purposes hereinafter set forth.

The load in the elevator car is weighed in any suitable manner as by the deflection of a spring-mounted platform PL. Loads in excess of say percent of rated capacity open the normally-closed load weighing switch LW, and close a normally-open load-weighing switch LWL Loads in excess of say l1() percent of rated capacity close the normally-open switches LW2 and LW3.

, FIGURE 2 Fig. 2 shows circuits for the driving motor, the brake. the speed relay V, the up switch U, the down switch D, the car-running relay M, the holding relay G, the slowdown inductor relay E, the stopping inductor relay F,

the up-preference relay W, the down-preference relay X,

the timing relay 70T, the door relay 40, the door-control relay 45, the door-close relay DC, the door-open relay DO, the detector relay SR, the time-delay relay SRT and the expediter relay 3h0. Energy for the various circuits is derived from direct-current buses L| and L.

Although various motor control circuits may be employed, it will be assumed that a control circuit of the variable-voltage type is employed. By inspection of 2, it will be noted that the armature A of the driving motor 15 and the armature 29A of a direct-current generator 29, together with a series eld winding 29B for the generator, are connected in a series or loop circuit. The eld winding 15B for the driving motor 15 is connected directly across the buses L-I- and L The magnitude and direction of energization of the driving motor 15 are controlled by the direction and magnitude of the energization of a separately-excited field winding 29C provided for the generator 29. It will be understood that the armature 29A of the generator is rotated at a substantially constant rate by a suitable motor MO which may be a polyphase induction motor energized `from a suitable polyphase source of energy through a switch MOS. Contacts lMOS1 are illustrated and are operated by the switch to closed position only when the motor MO is conditioned to run. For present purposes, it will be assumed that operation of the switch MOS to closed position also closes the contacts MOSl.

The switch MOS is biased towards open condition, and when closed is held in closed condition by a latch LA which is biased away from latching position and which is operated to latching position by energization ol'` a solenoid. (The latch is shown in latching position.) The solenoid is energized through break contacts OLt of an overload relay OL. For illustrative purposes it is assumed that the relay OL is energized from a phase conductor of the power source supplying the motor MO through a current transformer TR. When the current supplied to the motor increases to an excessive value indicating that the elevator car is overloaded or stalled, the relay OL picks up to interrupt the energization of the solenoid of the latch LA provided that a holding circuit including the make contacts 7tlT5, LW2 and 72T1 is open. As a result of such deenergization the switch MOS opens.

As shown in Fig. 2 the buses L+ and L- are energized from a suitable source of direct current through contacts MOS?. which are closed only when the switch MOS is closed.

When the elevator car A is conditioned for up travel, the generator eld winding 29C is connected across the buses L+, 1.- through make .contacts U2 and U3 of the up switch. When the elevator car A is conditioned for down travel, the generator field winding 29C is connected across the buses through the make contacts D2 and D3 of the down switch. The energizing circuit for the iield winding may include a resistor R1 which is shunted by make contacts V1 of the speed relay V. By inspection of Fig. 2, it will be observed that the contacts U2, U3, D2 and D3 constitute in effect a reversing switch for controlling the direction of energization of the .eld winding. The resistors R1 and the contacts Vl are provided for controlling the magnitude of energization of the field winding.

The speed relay V may be energized through either of two circuits. tacts Ud of the up switch U, a limit switch 30 which is One of the circuits includes make con-v normally closed and which is opened as the elevator car A nears the upper limit of its travel and the break contacts E1 of the slowdown inductor relay E. The other circuit is completed through make contacts D4 of the down switch D, mechanical limit switch 31 which is normally closed and which is opened as the elevator car nears the lower limit lof its travel in the down direction, and break contacts E2 of the slowdown inductor relay.

A time-delay relay 72T is energized from the buses L-land L through make contacts V4 of the speed relay V, or break contacts M11 of the running relay M. When deenergized this relay 72T has a substantial delay in dropout. The time delay is represented by a resistor connected across the relay.

As previously pointed out, the brake 17 normally is spring-biased into engagement with the brake drum 16 and is released by energization of a brake coil 17B. The `coil may be energized either throughfmake contacts U1 of the up switch U or through make contacts D1 of the down switch D.

In order to energize the car-running relay M, certain safety devices 33 must be in their safe conditions. Such safety devices may include switches which are open when the doors of the elevator car land the associated hoistway doors are open, and which are closed when the doors are closed to control the door relay 4t). Such safety devices are well known in the art. The car-running relay M may be energized through either of two circuits. One of the circuits includes the make contacts 89-1 of the starting relay 80, make contacts W1 of the 1tip-preference relay W, break contacts F1 of the stopping-inductor relay, normally-closed contacts of a mechanical limit switch 34 -which are opened when the car nears the upper limit of its travel, and the coil of the up switch U. When energized, the up switch U closes its make contacts U5 to complete a holding circuit around the contacts -1 and W1.

The second circuit for energizing the car-running relay M includes the contacts 80-1.of the starting relay, make contacts X1 of the down-preference relay X, break contacts F2 of the inductor stopping relay, normally-closed contacts of a mechanical limit switch 35 which are opened as the elevator car nears the lower limit of its travel in the down direction and the coil of the down switch D.

When the down switch D is energized, make contacts` D5 are closed to provide a holding circuit around thecontacts 80-1 and X1.

Before the holding relay G and the inductor relays E and F can be energized, make contacts M1 of the car-- In addition, any one sety of make contacts l1 of the reversal relay, TTI of therunning relay must be closed.

car-call stopping relay, and K1 of the Hoor-call stopping relay must be energized. A holding circuit around these.

contacts is established upon closure of the make contacts G1. Energization of the inductor stopping relay F further requires closure of the break contacts V2 of the,

speed relay.

If the break contacts J2 of the reversal relay are closed,-

the up-preference relay W is energized only if the elevator car is not operating in the down direction (break con. tacts D6 are closed); the elevator car is not conditioned.v

limit switch 37. The mechanical limit switch 37 is open when the elevator car A is adjacent the first or dispatching floor. y

The doors for the elevator car A are controlled by .a door-control relay 45. For this relay to be initially energized, and assuming that the manual switches 64,

13 642B and tl are open, the break contacts N1 and TNlt must be closed to indicate that the'elevatorcar is not being loaded at a terminal door. Break contacts 70HT2 must be closed to indicate that noneinterference time allowcd for a corridor or floor call has elapsed or the switch 64 must be closed. ln addition, the break contacts 70T1 must be closed to indicate that the general non-interference time has expired. The switch SE1 must be closed to indicate that the safety edge SE of the door is not dellected. The make contactsSRl must be closed to indicate that no object is positioned in the closing path of the door. The break contacts '70-1 must be closed to indicate that an auxiliary or shortened non-interference time has expired. Finally, the make conta-cts REI must be closed to indicate that the door is not to reopen. When the relay 45 picks up, it closes make contacts 45-1 to partially complete a holding circuit for the relay.

lf the switch 9d is closed, the energization of the relay 45 is further controlled by two circuits, one containing the switch MOSL and make contacts 45-4. The remaining circuit contains a camoperated switch 68 which is open only when the elevator car is at the lower terminal door, a switch TS1 which is open only when the elevator car is assigned for down peak operation and break contacts NU of a timing relay.

Should the satety-edge contacts SE1 be held open for an unreasonably long time (a door-hold button could be provided to control the relay 45'in a similar manner) or should the beams of light across the doorway be interrupted for an unreasonably long time, the break contacts NUAl close to establish with the contacts TNI and Nl an energizing circuit for the relay 45.

The door-control relay 45 controls the energization of the door-close solenoid DC and the door-open solenoid DO. If the contacts 45-2 of the door-control relay are closed, and the break contacts 40-2 are closed, the solenoid DC is energized. The contacts 40-2 are closed when the door of the elevator car A or an associated hoistway door is away from its closed condition. lf a manual switch 64A is open the energization of the solenoid DC also is co-ntrolled by the contacts SES and SEAZ in parallel.

If the door-control relay 45 is dropped out, the make contacts 45-3 are closed to, complete withthe switch 38 an energizing circuit for the door-open solenoid DO. The switch 38 is a limit switch which is normally closed and which is opened as the door reaches its fully-open position.

The timing relay 70T is connected for energization by make contacts M of the car-running relay. The energizing circuit is completed through break contacts 300-1 of an eXpediter relay. It Will be noted that a resistor R2 is connected across the timing relay 70T and the contacts 30G-1. lf the timing relay is energized and the contacts M5 thereafter open, the resistor R2 delays the dropout of the timing relay 70T for a suitable non-interference time, such as 5 seconds. lf the contacts 3004 open, the relay 70T drops out promptly. The eective resistance value of the resistor R2 is controlled by break contacts TLS and L3 to decrease the time delay when the car is at a terminal llo-or to a value such as 2 seconds.

The retector relay SR is controlled by the make contacts PRI-l and PRE-2l. These contacts are closed respectively as long as the photocells PCI and PC2 (Fig. `l) are illuminated by their respective radiant energy beams. The contacts may be bypassed by operation of a manual switch 62, or by operation of a manual switch 62A which `is in series with the switch 38B which is closed as long as the door is within say ten inches of fully-open position.

Break contacts SR2 and SRS of the relay SR respectively control the energization of the time delay relay SRT and the expediter relay 300. The time delay relay SRT may have a time delay in dropout of the order of onehalf second.

The expediter relay 300 `also may be energized by closure of contacts 5l. These contacts may be arranged -to close whenever a car call is registered in the elevator car A for the purpose of cxpediting departure of the elevator car from floor at which it is stopped. For present purposes it will be assumed `that the contacts Si represent a push button which is located in the elevator car A and which is operated to expedite departure of the elevator car from a floor.

Although the lamps LA and LAZ of Fig. l may be continuously illuminated, they are illustrated in Fig. 2 as illuminated through break contacts M6 of the carrunning relay M.

FIGURE 3 Fig. 3 illustrates additional circuits for controlling door aperation and circuits for energizing the car-call stopping relay TT, :and the floor-call stopping relay K.

`lf make contacts K2 of the licor-call stopping relay and the break contacts I3 of the reversal relay are both closed, the timing relay 'NHT is energized land picked up. This relay has a time delay in dropout determined Iby a resistor R3 which may 'ce of the order of two seconds to establish a shortened non-interference time under certain conditions. if a different time is desired at a certain floor a mechanical switch 69 may be operated at such floor to modify the `dropout time. ln the present oase the switch closes to shunt a portion of the timing 4resistor R3 in order to increase the dropout time to say three seconds.

IMake -co-ntacts 7tHTl and SRTll in parallel control the energization of an auxiliary relay 7%.

Make contacts SRfi control the energization of a timing relay NU. This relay has a time delay in dropout. (determined by a resistor kR/) which may be of the order of four seconds.

Make contacts SRS of the detector relay SR and the contacts SEZ operated by the safety edge SE control in part the energization of a timing relay NUA which has a time delay in dropout of say twelve seconds as determined by `a resistor R5. lf the relay NUA is picked up, -opening of make contacts LWAll drops out the relay promptly.

The timing relay LWA is energized through any of four paths. One path contains the break contacts LW of the load weighing switch LW. A second path contains break contacts of a switch 68A which is closed only when the elevator car is at the bottom terminal floor and contacts T83 which are closed only duringdown peak periods. The lthird path has contacts of a mechanical switch orl which is closed only when the elevator car is away from the terminal floors and contacts T84 which are closed only during up peak periods. The fourth path contains a limit switch 38C which is open only when the door is open.

The car-call push buttons 2c to 5c normally are biaser into their open positions against back contacts 2cx to Sex. The button lc for the tirst landing does not have `such back contacts. Each of the push buttons is provided with :a holding coil icc to 5cc, which is effective forholding the associated pushbutton in its operated condition following a manual operation of such pushbutton. To this end, the pushbuttons may be made of magnetic material. Such construction of `the pushbuttonsI is well known in the art.

Each of the pushbuttons 2c to 5c has front contacts controlling the connection of contact segments to the bus L+. When operated, the push button 2c connects the Contact segments a2 and /z to the bus L+. The push buttons 3c and tc similarly connect contact segments for the third and fourth iioors to the bus L+. inasmuch as the elevato-r car is assumed to stop at the fifth door or upper terminal tloor at all times during up ravel, the contact segment a5' is permanently connected to the bus L+. Similarly, during down travel, the elevator car A always `stops when it reaches the -rst licor, and the contact seg le' ment h1 for the first llo-or `is permanently' connected to the bus L+.

lt will be understood that the contact segments a2 to a `are Iarranged in a row on the tloor selector 19 of Fig. l and are successively engaged by `a brush Z3 as the elevator car moves from its lower limit to its upper limit of travel. `In a similar manner, the contact segments h4 to h1 are arranged in a row in the order of the floors for successive engagement by a brush 4th: as the elevator car moves from the upper terminal to its lower limit of travel.

-During up travel of the elevator car A, the car-call stopping relay TT is connected between the brush 23 and the bus L- through make contacts W3 ofthe up-preference relay and make contacts M3 of the car-running relay. Consequently, when the brush Z3 reaches one of the contact segments a2 to a5 which is connected to the bus L+, the oar-call stopping relay TT is connected for energization Vacross the buses L+ and L- for the purpose of stopping the elevator car at the next floor reached by the car. As the elevator car stops, the brush 23 preferably passes slightly beyond the associated contact segment.

When the elevator car A is conditioned for down travel, the car-call stopping relay TT is connected between the brush 40a and the bus L- through the make contacts X3 of the down-preference relay and the make contacts M3 of the car-running relay. Consequently, when the brush 49a reaches one of the contact segments h4 to h1 which is connected to the bus L+, the car-call stopping relay TT is energized to initiate a stopping operation of the elevator car at the next floor reached by the car. As the elevator car stops, `the brush 40a preferably passes slightly beyond the associated contact segment.

The coils cc to 5cc are connected in series for energization either through make contacts W4 of the 11p-preference relay or m-ake contacts X4 of the down-preference relay. When the elevator car reverses its direction of travel, the make contacts W-and X4 both are momentarily opened to deenergize the associated holding coils for the purpose of resetting the car-call push buttons.

Each of the push buttons 1c to 5c when operated opens a set of contacts ley to Scy respectively. These contacts control a reopening operation of the door which will be discussed below.

Each of the car-call buttons when operated also opens an auxiliary set of normally-closed contacts 2cx, 3cx and 4ax respectively. These are employed in a high call circuit which will be discussed below. A set of contacts Sex and a holding coil 5cc also are provided for the fifth tloor.

When the down floor-call push button 2D is operated, the down floor-call storing relay 2DR is connected therethrough across the buses L+ andAL- for energization. Upon energization, the relay closes its make contacts ZDRIL to establish a holding circuit around the push button. The contact segment f2 now is connected (and corresponding contact segments for the remaining elevator cars are connected) through the contacts ZDRl to the bus L+. The contact segments f4 and f3 similarly are connected to the bus L+ by operation of the down hoor-call push buttons 4D and 3D. The contact segments f4, f3 and f2 for the fourth, third, and second floors are positioned in a row on the oor selector 19 of Fig. l for successive engagement by a brush 58 as the` elevator car A moves from the upper terminal in a down direction. l

Fl`he hoor-call stopping relay K is connected between the bus L+ and the brush 58 through make contacts X5 of the down-preference relay. Consequently, if the ele-- vator car A approaches the second floor during a down trip while a down oor call is registered for such floor the engagement of the contact segment f2 by the brush 5S completes an energizing circuit for the licor-call stopping relay K.

Each of the down Hoor-call storing relays 4DR, 3DR and 2DR has an operating coil and a cancelling coil, respectively, 4DRN, SDRN and ZDRN which is energized in opposition to the energization of the operating coil. The cancelling coil 2DRN is connected between a contact segment g2 (and similar contact segments BgZ etc. for the other elevator cars) and the bus L+ through the make contacts 2DR1. As the elevator car A reaches the second floor, the following energizing circuit for the cancelling coil is established:

L+, 2DR1, ZDRN, g2, 59, X6, M4, L-

Energization of the coil ZDRN opposes energization of the relay by the operating coil and resets the relay. It will be understood that the contact segments g4, g3 and g2 are arranged in a row for successive engagement by the brush 59 as the elevator car proceeds downwardly from the upper terminal floor to control the energization of the cancelling coils 4DRN, SDRN and ZDRN.

The down oor-call storing relays all cooperate with the brushes 58 and 59 in substantially the same manner to control the :energization of the oor-call stopping relay during down travel of the elevator car.

When the up hoor-call push button 2U is operated, the up floor-call storing relay ZUR is connected for energization therethrough across the buses L+ and L Upon operation, the relay closes its make contacts 2UR1 to establish a holding circuit around the push button 2U. As a result, a contact segment b2 is connected (and contact segments Bb2 etc. for the other elevator cars are connected) to the bus L+ through such make contacts.

As the elevator car during up travel approaches the second floor, the brush 60 engages the contact segment b2 to establish the following energizing circuit for the floor-call stopping relay:

L+, 2UR1, b2, 60, W5, K, L-

This conditions the elevator to stop at the second floor. As the elevator car stops at the second oor, a brush 61 engages the Contact segment c2 to establish the following circuit for the cancelling coil of the storing relay ZUR:

L+, ZURI, ZURN, c2, 61, W6, M4, L-

Such energization of the cancelling coil results in resetting of the storing relay which has its main coil acting in opposition to the cancelling coil. The up floor-call push buttons 3U and 4U similarly control the associated storing relays and contact segments. It will be understood that the contact segments c2, c3 and c4, and contact segments b2, b3 and b4 are arranged in rows on the oor selector forengagement successively by the brushes 61 and 60, as the elevator car A proceeds upwardly.

FIGURE 4 In Fig. 4 a starting relay 80, a dispatching device which normally controls the lower terminal dispatching of the elevator cars employed in the system, and a reversal relay J are illustrated.

The starting relay S0 can be energized only if the timing relay 70T is deenergized and dropped out to close its break contacts 70T2. If additional non-interference time is allowed for a corridor or oor call, the manual switch is open and break contacts 70HT3 of the timing relay also must be closed to permit energization of the relay 80. When the elevator car is positioned at the lower dispatching oor, the energizing circuit for the starting relay normally is completed through the make contacts S1 of an auxiliary starting relay. At the upper terminal or dispatching floor, make contacts UTSI may operate. in a manner similar to the operation of the contacts S1 for the lower dispatching floor to start the elevator car from the upper terminal oor. Between the dispatching tloors, the make contacts S1 are shunted by the 17 upper terminal or dispatching iloor and the lower` dispatching iloor. For all other positions of the elevator car A, the switch 63 is closed.

The selection and timing mechanism include as one component a motor 71 which operates substantially at constant speed. This motor may be of any suitable type, but for present purposes it will be assumed that the motor is a squirrel-cage alternating-current motor'whch is energized from a suitable source of alternating current. The motor 71 is connected through a spring-released electromagnetically-applied clutch 72 to a cam 73 having a protuberance for successively operating mechanical switches Y, BY, CY and DY which are associated with the respective elevator cars. The electromagnetic clutch can be energized only if one or more elevator cars are located at the dispatching floor which is assumed to be the first hoor (one or more of thek contacts L1, BL1, CLl, DLI are closed), and if no elevator car has been selected as the next car to leave the dispatching floor (break contacts N2, BNZ, CN2 and DNZ all are closed).

The motor 71 also may be coupled through a springlreleased electromagnetically applied clutch 74 to a cam 75 which is biased towards a predetermined position by a spring 76. The cam 75, when coupled to. the motor 71, is rotated against the bias of the spring to close normally-open contacts 7.7 a predetermined time after the earn 75 is Acoupled to the motor 71,. The clutch 74 can be yelectrically energized only if no elevator car is being started (break contacts S2, BSZ,v CS2 and DS2 are closed), and if the break contacts 1S1 of the holding relay 1S are closed. The lholding relay 1S is energized upon closure of the 'contacts 77 to close its make contacts v1S2.for the purpose of establishing a holding circuit around the contacts 77.

The presence of an elevator carat the dispatching door is determined by the energization of `a car-position relay foreach of the elevator cars. Thus, a car-position relay L for the elevator car A is energized when the brush 24 engages .the contactsegment el.

The brush24 is operated by the oor selector for the elevator car A to engage the contact segment le1 when the elevator car is at the dispatching floor.

If the elevator car A is yat the dispatching ,floor (make contacts L2vare closed), if it has been selected as the next car to .leave the dispatching oor (switch Y is closed), Vand ifitis not being started (break contacts S3 are closed), .theloading .relay N .for ithe .elevator car A is energized The loading relay :may be employed in :a

conventional vway to permit loading of t-he .elevator .Car A. vFor example, the loading relay when Yenergizedmay operate a loading signal, such as a lamp, which Jindicates that passengers may enter the .elevator car. Conveniently, theloading relay N when energized opensthenor-mallyyclosed doors of the elevator car ,A tto permit entry of Therelay S when .energized-closes its ,make contacts ,S4 to establish .a holding circuit around the contacts :,N'and ISS, and .starts the elevator car 4A from the .dispatching door.

'If thetelevator car is loaded before expiration of the interval measured by the relay y1S it may bezadvisableto expedite .departure of the car. To vth'is end'fazmanual switch .99 may be closed :to t'connect the relay '2S v for energization through any of four parallelcircuits, one for each of the elevator cars. The circuit for the elevator carA includes break contacts 7.0T3fofthemonfintererence relay, make contacts N4 rof .the loadingtrelay-.andfa .switch LWl whichis closed'only when .thegload Iin thefelevator can exceeds say 80 percent offrated capacity. Thus ifthe elevator car A is selected as the next cart to leavev the terminal oor (contacts N4 are closed), ifv the non-interference time has expired (contacts 70T3 are closed) and if the elevator car is fully loaded (switch LWl isy closed) the relay 2S picks up and closes its contacts 281. Since the contacts 2S1 shunt the contacts- 1S3, prior closure of the former contacts expedites dispatch ofthe elevator car.

Fig. 4 also discloses a reversal relay I which is connected between a brush 6 6 and theV bus L+. thro-ugh a manually-operated switch 67 and make contacts W7 of the 11p-preference relax The brush. 66 and an associated row efcentact segments k2, k3 and k.4, are included il? the floor selector of Fig. 1. The contact segments are associated withI a call circuit which includes break contacts of the call registering relaysv andv the contacts QCX, 4CX and SCX associated with the car call push but.- tons. By tracing this circuit in Fig. 4 it will' be noted that the bus L+ nis connected to the contact segment h2 through the following circuit:

c+, sDRz, SCX. 4UR2. 411112, 46X.. susa. sulla QX,

zum, k2

(A down iloor call registering relay is not illustrated in Fig. 3 for the fth oo-r, but it will be understood that the break contacts SDRZ of Fig7 4 are operated by a push button for the fifth door in the same manner by which break contacts 4DR2 are operated by its pushy button for the fourth floor.) Consequently, contacts of all call .are assumed to be open. i `floor, the switch 63 also is open. The timing 4relay registering relays or car call Ypush buttons which when operated require carV travel above the second floor are located between the contact circuit segments k2 for the second hoor and the bus L+.

The contact segment k3 is connected to the call circuit between the contacts 3U`R2 and 3DR2`. QllSelllently, contacts of all call registering relays or car call push buttons requiring travel of the elevator car above the third floor are located between the contact segment k3 for the third Heer and the bus L+. In an analogous manner, the contact segment 4 for ,the fourth ,desir is connected to the call circuit at a point between the con tacts 4UR2 and 4DR2. Such call circuits are well known in the art.

The contacts Icy to Scy which are loperated by the car-call push buttons are connected in series with the operating coil of the reopen relay YRE across thev buses L+ and vL. The relay also may be energized through any et the make Contacts N5, IN-5, S5 and UTSS of the loading and auxiliary starting relays f or the terminal landings. Finally, t-he relay RE may be .energized through the break contacts L4 and TL4 of @the car-position relays.

When the reopen relay operates, it opens break contacts REZ to deenergize a suitable signal, such as a sign indicating that another car will be the next to leave the door.

Operation AIn order to explain the overall operation of the Aelev ator system, it will be assumed rst that the elevator cars are at the iirst or dispatching door the initially is energized. The cars are conditioned for operation in the up direction. lFor example, the switches MOS and MOS1 are closed and the elevator car A has its up-.preference relay W energized. Consequently, make contacts W1, W2, W3, W4, W5,'W6, W7 ofthe relay are closed, whereas break contacts'WZ yof the relayare yopen.

Timedelay relay 72T is energized yand pickedup.

rThe switches 62A, 90 (Fig. 2), 63A and,67 (Eig. 4)

Since the cars are yatlthe -iirst T is assumed to have timed out. 'The relays :SR, 45

:and 40 are picked up and the elevator car -doorsare closed. Switches 64A, 64B, 64C, 67S1 and 68Ay are The motor 71 (Fig. 4) is energized to rotate ata substantially constant rate.

Inasmuch as the elevator cars are assumed to be at the dispatching floor, thecar-position relays L, etc. are energized.

As a result of its energization, the car-position relay L closes its make contacts L2 to prepare certain circuits for subsequent energization. In addition, the make contacts L1 close to complete the following circuit for the clutch 72.

L+, L1, 72, N2, BN2, CN2, DNZ, L-

The clutch now couples the motor 71 to the cam 73 for the purpose of successively closing and opening the associated mechanical switches. It will be assumed that the first switch reached by the cam is the switch Y for the elevator car A. Closure of this switch completes the following energizing circuit for the loading relay of the elevator car A:

L+, L2, N, S3, Y, L-

The loading relay N upon energization initiates opening of normally-closed doors of the elevator car A to permit intending passengers on the dispatching oor toV enter the elevator car. Such opening is eiected by opening of contacts N1 (Fig. 2) to deenergize the door-control relay 45. This relay opens its contacts 45-1 and 45-2 without immediate effect on system operation. However, closure of contacts 45-3 energizes the solenoid DO to open the doors. In opening, the door opens its set of contacts 33 to deenergize the door relay 40 which opens its contacts 40-1 and closes its contacts 40-2 without immediate effect on system operation. When the door reaches a position say ten inches from fully-open position the switch 38B closes. On reaching a position say one inch from fully-open position the door opens the switch 38A. These switch operations have no irnmediate eiect on the system. When it reaches open position, the door opens limit switch 38 to deenergize the solenoid DO.

Opening of the break contacts N2 (Fig. 4) deenergizes the clutch 72. Consequently, the cam 73 is uncoupled from the motor 71. T he make contacts N3 close to prepare the starting relay S for subsequent energization. Closure of the make contacts does not affect the immediate operation of the system.

When the system was placed in operation, the clutch 74 was energized through the circuit:

L+, 1S1, 74, S2, ABSZ, CS2, DS2, L-

As a result of its coupling to the motor 71, the cam 75 rotates against the bias of its spring 76 until at the expiration of the time interval allowed for loading elevator cars the contacts 77 close. Closure of these contacts completes the following circuit:

L+, 1S, 77, S2, BS2, CS2, D52, L-

The energized relay 1S closes its make contacts 1S2 to establish a holding circuit around the contacts 77. The break contacts 1S1 open to deenergize the clutch 74, and the spring 76 now rotates the cam to its starting position. Also, the make contacts 1S3 close to energize the auxiliary starting relay S through the following circuit:

L+, L2, S, N3, 1S3, L-

Energization of the auxiliary starting relay S closes the make contacts S4 to establish a holding circuit around the contacts N3 and 1S3. Break contacts S3 open to deenergize the loading relay N. Break contacts S2 open, and this opening causes relay 1S to drop out. This has no immediate effect on the system operation. Ciosure of the make contacts S5 has no immediate eiect on operation of the system.

The loading relay when deenergized opens its make contacts N3 and N5 without immediate effect on the operation of the system. In addition, break contacts N2 operation.

tion.

The deenergization of the,y loading relay further closes break contacts N1 (Fig. 2) to 'complete with the contacts 70-1, SR1, 70T1 and TNI an energizing circuit for the door-control relay 45. The latter relay closes its make contacts 45-1 and opens its break contacts 45-3 without immediate effect on system operation. However, closure of make contacts 45-2 completes with the contacts 40-2 an energizing circuit for the door-close solenoid DC, and the door now starts to close. If the switch 62 is open and a passenger is in the closing path of the door, he interrupts one of the beams of radiant energy and one of the sets of contacts PRI-1 or PR2-2 opens to deenergize the detector relay SR. This relay then opens its make contacts SR1 to deenergize the doorcontrol relay 45. The latter opens its contacts 45-2 to deenergize the door-close solenoid and closes its contacts 45-3 to energize the door-open solenoid for the purpose of reopening a partly-closed door. The detector relay also closes its break contacts SR2 and SRS to energize the relays SRT and 300. The energization of the relay 300 has no effect at this time on the operation of the systemA but the energization of the relay SRT closes make contacts SRT1 to pick up the timing relay 70 (Fig. 3). This relay opens its break contacts 70-1. After the passenger clears the door closing path, the detector relay SR picks up to close its make contacts SR1, and open its break contacts SR2 and SRS. The resultant drop out of the relay 300 has no effect at this time on the system However, the opening of contacts SR2 starts a timing out operation of the relay SRT. After lthe expiration of its time delay, such as one-half second the relay SRT drops out to open its contacts SRT1 and such opening drops out relay 70. The relay 7i) closes its break contacts 70-1 to complete a circuit for the relay 45.

The operations of relays NU, NUA and LWA will be discussed below.

In some cases, it is desirable to prevent a reopening of the the door by the relay SR. In such a case, the manually-operated switch 90 may be closed to connect make contacts 45-4 of the door-control relay and the switch MOS1 around the contacts SR1 and 70-1. When the doorcontrol relay picks up, the resulting closure of its contacts 45-4 assures door closure despite subsequent drop out of the relay SR, provided that the switch M051 is closed to indicate that the motor generator set is running. For the following discussion, the switch 90 is con sidered to be open. Even with the switch 90 closed, if the door actually encounters a person, the safety edge would open the switch SE1 to deenergize the relay 45 and reopen the door.

It will be assumed however that no person is in the closing path and that the door closes. Upon closing, the door closes its switch 33 to complete an energizing circuit for the door relay 40 which closes its make contacts 40-1 and opens its break contacts 40-2 to denergize the door-close solenoid DC.

Turning now to Fig. 4, it will be noted that closure of the make contacts S1 results from energization of the auxiliary starting relay S. Inasrnuch as the elevator car A is assumed to have remained at the dispatching oer for a time sufficient to permit closure of the break contacts 70T2, an energizing circuit now is complete for the main starting relay 80. Switch 65 is assumed to be L+, -1, W1, F1, 34, U, M, 40-1, L-

The energized up switch U closes its make contact U1 to release the brake 17, and contacts U2 and U3 close to energize the generator eld winding 29C with proper .polarity'tfor .up travel of the elevator'car. vMake/contacts U4 close lto complete through the limit switch 30 and the contacts E1 an energizing; circuit 'for the speed relay V. The speed krelay closes its make contact V1 :tofshunt 'the resistor R1 and condition the elevator car A for full speed operationfin the up'direction. Also, thespeed relay opens its break contacts V2 to prevent energizationtherethrough of .the stopping A'inductor relay F. Closure of ymake contacts V3 establishes with contacts 45-l1, TNI and 'N1 a holding circuit for the lrelay 45. "Closure of make contacts V4 `maintains energization of the relay 72T following the opening of the contacts M11.

Returning to the up switch U, it will .be noted that closure ofthe make contacts U5 .establishes a holding circuit around the contacts 80-1and W1. Opening of the break contacts Uprevents energization therethrough cvf the down preference relay. The elevator car A now is 4in condition for 'full .speed operation .inthe up :direction -and Vdeparts .from the dispatching ioor.

It will be recalled that the .car-running relay M was VKenergized with the up switch U. The car-running relay closed its make contacts M1, M3, M4 and M7 (Fig. 3) without immediate effect kon the operation of the system.

Closure of the makecontac'ts M2 (Fig. 2) `with the switch 64C shunts the contacts V3. (Opening of break'contacts M6 deenergizes the lamps LA1 and LA2 if those are not continuously energized. However, continuous illumination of the lamps is assumed.) Closure of the make `contacts M5 energizes the tim-ingrelay 70T. This :relay iopens its ,break contacts 70T2 (Fig. -4) which .causes the starting relay -80 to become deenergized. Opening of break contacts 70T1 (Fig. 2) and closure ,of make contacts 70T5 do not immediately affect system 'operation.

It will be assumed now that the passenger Iin the-velevator car operates .thecar-callpush Vbutton 3c (Fig. :3) to .register a car call for the third oor. Such voperation opens the contacts 3cx and 3cy without immediate :etect on the system and connects the `contact segment a3 .and h3 .to .the bus L+. .As the elevator car nears the third floor, 'the brush 23 engages the contact segment .a3 to complete the following circuit for .the car-icall stopping relay TT:

The car-call stopping relay now closes its make contacts TTI (Fig. 2) to energize the holding relay G and the slow down inductor relay E through the closed contacts M1. Energization of the holding relay G completes through the make contacts G1 a holding circuit around the contacts TTI.

'When the elevator car A in its upward travel 4reaches the inductor plate UEP (Fig. 1) for the third 4floor, the'breakcontacts E1 are opened to deenergize the speed relay V (Fig. 2). The speed relay opens its break contacts V1 to introduce the resistor R1 in series with the generator v'field winding 29C. .The resultant reduction `in field current slows the elevator car to a landing speed. In addition, the speed relay V closes its break contacts V2 to complete through the contacts G1 and M1 anenergizing circuit for the stopping inductor relay F. Opening of the make contacts V3 has no immediate effect on system operation.

Opening of the make contacts V4 starts a timingout operation of the relay 72T. This relay may have a time delay in drop out of the order of six seconds. 4If the relay drops out such drop out indicates that the elevator car hasfailed toreach its stopping position within a reasonable time and is stalled.

Shortly -before the elevator car A in its continued .upward movement at .the landingspeed reaches .the .third floor, lthe inductor plate UFP for the third oor is adjacent .the stoppinginductor relayand completes a magneticcircuit whichresults in opening of the contacts F1.

22 .Opening of the `contacts EF1 fQFig. 32) /deenergizes the tup swfiteh aU :and the :car-running relay `.Therup 4switch U opens its make contactsUl vto deenergize the brake .1.7, :and fthe .brake is -promptly forced against the `b1ake-.drum 1.6 byits associated spring. Contacts U2 and U3 open to deenergize the generator field -wiuding 29C. Consequently, the jelevator car A 'stops yaccurately fat the third floor. 'Opening of "the make contacts U4 and yU5and 'closure yof the break contacts U6 have-no immediateeffect yon theoperation 'of the system. As the elevatorcar lcomes to'a-stopthebr-ush'23.mayl pass kthe .contact segment for aslight 'distance to ydeenerg'ize fthe relay "TT The :previously-mentioned deenergization ofthe lcarrunning relay resulted in opening of the make lcontacts M1 to deenergize the inductorrelays "Eand Fan'd the 4holding relayfG. vThe-'holding `relay `G-opened its make contacts G1 Iwithout limmediately affecting Ithe operation ofthe system.

-The car-running relay also opened its make Acontacts `tM5 to start atiming-out operation of the timing relay 170T. Contacts I'MS preferablyopen with a-slight time 'delay to 'assure prior rcflosureof v`contacts 3D0-1. This Arelay"7t)-'l"'has fa-time'iilelay in drop out-sucient to permit discharge of passengers-orentry of lpassengers -into the elevator c'ar A. 'For example, a time'delay off've seconds may be employed. Opening of the make conttacts M3 and closure o'fthe'breakcontacts M4 have no immediate effect on the operation vof the system. (If continuous lillumination of the lamps is lnotemployed, closure `of vcontacts M6 Ailluminates the lamps LAI and LAZ, :and theseiillurninate their'associated photocells'ffto rclose contacts APRI-l1 and TR2-"1 'which pick up "relay 'SR. 'lhe pick up'fo'ffrel'ayfSR andrtherestilting deener- Agiza'tionofirelaysSRT and rv'300 have noimmediateeifect on the 'operation except that closure of contact l300-1 `facilitates Jthe previously mentioned energization o'f the relay 70T.) However, the relay vSRT `'starts \to 'time rout.

Closure-fof the break contactsMl'l reenergizes thev relay 72T. Normally this occurs before the rel-ay ycan ydrop out.

'Opening :of make contacts M2 deenergizes the door control krelay 45 and this relay vopens its makefcontacts -`4`5-i1fand y45-"2 without immediate effect on system-'operation. However, closure of break contacts 4S-3 completes with the lswitch 38 a circuit for the door-openlsolen'oidDO and the door now opens. In opening, the 'door opens'its -switch 33 to deener-gize the 'door 'relay '40 without immediate etect on system operation.

Let it-beassumed thatinsteaddfafcar call, an up oor call was registered "for thethird oorby operation of'the push button 3U (Fig. 3). Such Voperation energizes the up oor call storingrelay3UR which closes its make contacts GURI to establish `a holding circuit around the push button. The contacts -3UR`1also serve to connect the contact segment b3 and 'corresponding contact y'segments'for the remaining elevator cars of'the system to thebus L+. Opening of contacts 3UR2 Yand '3UR3 does not `affect the operation o'f the system at this time.

As the elevator car approaches the third oor, .the :brush 60 .engages "the contact segment b3 `to energize the .oor-call stopping .relay K through the following '.cir cuit:

Upon energization, the oor call stopping'relay closes its make contacts K1 (Fig. 2) to energize throughthe contacts M1 the holding relay'G, the slowdown inductor relay'E and the stopping inductor relay 1F. These Vrelays operate inthe'same manner previously discussed to stop the elevator car `accurately at the third floor. lContacts KZof .theoor callstopping relay also close tocomplete with .the .contacts J3 an'energizing circuit .forzthe relay 76H1". TheV latterrelay 70HT closes :its .makecontaicts 70HT1 and opens break .contacts 70HT2 and 70HT:3 

